Forgive me if this has been discussed already.
I don't know why it irritates me so much, perhaps it is because it makes me feel it is like receiving junk mail, except from distant relatives.
Or maybe it is the inference that people who do this have so many friends / such a fulfilled life, that they simply don't have the time to write the envelopes.
Whatever the reason, anyone who sends a Christmas card to me, and uses an address label on the envelope, receives a mental blackmark against them.
Is it just me?